An Update on "Paraíba" Tourmaline from Brazil

Shigley, James E.; Cook, Brian C.; Laurs, Brendan M.; Bernardes, Marcelo de Oliveira

doi:10.5741/gems.37.4.260

Cited by 18 publications

(28 citation statements)

References 22 publications

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“…According to these authors, Zn contents of this order of magnitude are not found in pegmatites of the LCT family (classification of Černý 1991). The great majority of the elbaite data from the BPP, including the data on "Paraíba tourmaline", reveal low Zn contents, 0.01 to 0.26 wt.% ZnO according to Rossman et al (1991), or 0 to 0.50 wt.% ZnO according to Shigley et al (2001). The Zn contents of the tourmaline crystals analyzed in this study also are usually low (<0.55 ZnO wt.%).…”

Section: Major and Trace Elementmentioning

confidence: 81%

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Compositional Variation of Tourmaline-Group Minerals in the Borborema Pegmatite Province, Northeastern Brazil

Soares¹,

Beurlen²,

Barreto³

et al. 2008

The Canadian Mineralogist

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Various species of the tourmaline-group are common accessory minerals in the Boqueirão, Capoeira and Quintos Li-Be-Ta-Nb-bearing, LCT-family, rare-element-class granitic pegmatites from the Borborema Pegmatite Province (BPP), northeastern Brazil. Tourmaline from the border and wall zones of the pegmatites is enriched in Mg and Fe, crystallizing as Mg-rich members of the dravite-schorl solid-solution series. Tourmaline from the intermediate zone is richer in Fe and Al+Li, crystallizing as schorl. The Fe-Mg-free and Li-Al-rich elbaite is typical of the transition between the intermediate zone and the quartz core, and of replacement pockets. The bright turquoise blue elbaite known as "Paraíba tourmaline" is produced in the Capoeira 2 and Quintos pegmatites and is distinguished by high Cu contents, up to 1.07 wt.% CuO. In other occurrences of the "Paraíba tourmaline" in the BPP, up to 2.37 wt.% CuO were reported. Differences in the geochemical evolution trend of tourmalines among the pegmatite bodies investigated (vacancy at the X site, Fe, Mg, Zn, Li and F contents), suggest that they reached variable degrees of fractionation. This observation agrees with chemical data on white mica, feldspar, garnet and gahnite, and therefore permits the use of tourmaline composition as an indicator of the degree of evolution of the hosting pegmatite. According to these data,"Paraíba tourmaline"-producing pegmatites share the following characteristics: 1) they are the most evolved pegmatites so far known in § Volume 46October 2008 Part 5 the cANADiAN miNeRALogist the BPP; 2) they are hosted by quartzites or metaconglomerates (iron-poor host rocks); 3) they exhibit comb-textured dravite in the border zone (early saturation in tourmaline) and 4) the elbaitic "Paraíba tourmaline" is found in the most evolved parts of the pegmatites.sommAiRe De diverses espèces de tourmaline sont présentes comme accessoires dans les pegmatites granitiques de Boqueirão, Capoeira et Quintos, enrichies en éléments rares (Li-Be-Ta-Nb) et de type LCT, situées dans la province pegmatitique de Borborema (BPP), nord-est du Brésil. Dans les zones de bordure et de paroi des pegmatites, la tourmaline est enrichie en Mg et Fe; les compositions sont des membres magnésiens de la solution solide entre dravite et schorl. Dans la zone intermédaire, la tourmaline est enrichie en Fe et Al + Li, et correspond à la composition de schorl. L'elbaïte dépourvue de Fe-Mg et enrichie en Li-Al est typique de transition entre la zone intermédiaire et le noyau de quartz, et des poches de remplacement. L'elbaïte bleu turquoise connue sous le nom de "tourmaline de Paraíba" se rencontre dans les pegmatites de Capoeira 2 et Quintos, et se distingue par des teneurs élevées en Cu, atteignant jusqu'à 1.07% de CuO (poids). Dans d'autres indices de ce genre d'elbaïte dans la ceinture BPP, on a signalé jusqu'à 2.37% de CuO. Des différences dans les tracés géochimiques évolutifs des tourmalines parmi les massifs de pegmatites étudiés, par exemple dans la proportion de lacunes au site X, et de...

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Section: Major and Trace Elementmentioning

confidence: 81%

“…The striking neon-blue "Paraíba tourmaline" invariably is characterized by high Cu contents, with up to 2.32 wt.% CuO (Abduriyim et al 2006, Fritsch et al 1990, Henn & Bank 1990, Shigley et al 2001. In elbaite of other colors, copper is usually below the detection limit or present only in trace amounts (<0.56 wt.% CuO).…”

Section: Major and Trace Elementmentioning

confidence: 97%

Compositional Variation of Tourmaline-Group Minerals in the Borborema Pegmatite Province, Northeastern Brazil

Soares¹,

Beurlen²,

Barreto³

et al. 2008

The Canadian Mineralogist

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“…Lepidolite, quartz, and feldspar have not been reported as mineral inclusions in Cu-bearing tourmaline from Brazil or Nigeria (e.g., Fritsch et al, 1990;Shigley et al, 2001), although Abduriyim et al (2006) did report "hexagonal mica platelets" in Cu-bearing tourmaline from Nigeria. In any case, these minerals should probably not be considered locality-specific inclusions, since they have been encountered in elbaite from many different sources (see, e.g., Koivula, 2005).…”

Section: Discussionmentioning

confidence: 99%

“…Soon after its discovery in Brazil's Paraíba State in the late 1980s (Koivula and Kammerling, 1989), the material gained notoriety for its beautiful "neon" colors, and prices escalated rapidly. Additional deposits were found in Paraíba and in neighboring Rio Grande do Norte State during the 1990s (Shigley et al, 2001). Then, in 2001, Cu-bearing tourmaline was discovered in Nigeria (Smith et al, 2001).…”

mentioning

confidence: 99%

Copper-bearing (Paraíba-type) Tourmaline from Mozambique

Laurs¹,

Zwaan²,

Breeding³

et al. 2008

Gems & Gemology

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“…After the discovery of blue-green elbaite from the Batalha, the state of Paraiba, similar copper-bearing elbaites were found in granitic pegmatites at the nearby localitie of Mulungu and Alto dos Quintos in the state of Rio Grande del Norte (Karfunkel and Wegner 1996;Shigley et al 2001;Milisenda 2005). The chemical composition of blue or blue-green elbaites from Mulungu and Alto dos Quintos mines indicates a lower CuO content than of elbaite from Batalha (up to 0.8 wt% CuO versus up to 2.4 wt% CuO, respectively).…”

Section: Methodsmentioning

confidence: 95%